Earth boring tools for oil and gas exploration are typically produced by machining a graphite mold and filling the mold with tungsten carbide (WC) powder. A lower melting point alloy (often copper-based) is placed on top of the WC powder as an infiltrant metal binder. The mold is placed into a vacuum furnace which melts the infiltrant to fill the void space between the WC particles by capillary force, thereby binding the WC particles together and creating a hard metal reinforced composite structure in the shape of an earth boring tool. This process is limited to coarse grain tungsten carbide with a limited volume fraction (up to 60 volume percent) and low melting point infiltrants. The Cu-based infiltrated WC materials have inferior mechanical and wear properties relative to WC—Co grades, which have with finer grain size, higher volume WC content and much stronger cobalt, nickel or iron metal binders. The current technology of graphite mold machining, core inserts and infiltration process is a time consuming and expensive process with geometric limitation. In addition, the solid carbide structure uses excessive amount of WC, which results in an increased weight of the boring tool.